Forced air freezer

ABSTRACT

A refrigeration apparatus that has substantially uniform temperature throughout a storage enclosure in the apparatus comprising boundary walls defining the enclosure, an air duct substantially coextensive with a major portion of one of the walls and having edges adjacent others of the walls that are adjacent the one wall, peripheral discharge means at the air duct edges for directing air from the duct along the adjacent wall and toward a second wall that is directly opposite the one wall for flow of the discharge air along this second wall also, an air inlet adjacent one end of the duct for receiving air from the enclosure including the air that flows into the enclosure from along the second wall, means for forcing air through the air duct and means for refrigerating the duct air.

United States Patent Inventors Charles R. Dill;

Sylvester A. Winterheimer, Evansville, Ind. Appl. No. 800,081 Filed Feb. 18, 1969 Patented Apr. 13, 1971 Assignee Whirlpool Corporation FORCED AIR FREEZER 9 Claims, 2 Drawing Figs.

US. Cl 62/408, 62/419 Int. Cl F25d 17/04 Field of Search 62/408, 419

References Cited UNITED STATES PATENTS 2,331,560 10/ 1943 Mamsealer 62/408 2,767,558 10/1956 Wallenbrock 62/419 2,960,844 1 l/ 1960 Quick 62/408 3,364,696 l/l968 Maxwell.. 62/419 3,370,439 2/ l 968 Rivard 62/419 Primary Examiner-William .l. Wye Att0rney-H0fgren, Wegner, Allen, Stellman & McCord ABSTRACT: A refrigeration apparatus that has substantially uniform temperature throughout a storage enclosure in the apparatus comprising boundary walls defining the enclosure, an air duct substantially coextensive with a major portion of one of the walls and having edges adjacent others of the walls that are adjacent the one wall, peripheral discharge means at the air duct edges for directing air from the duct along the adjacent wall and toward a second wall that is directly opposite the one wall for flow of the discharge air along this second wall also, an air inlet adjacent one end of the duct for receiving air from the enclosure including the air that flows into the enclosure from along the second wall, means for forcing air through the air duct and means for refrigerating the duct air.

Patented A ril 13, 1971 FIGZ FIGI

INVENTORS ATTORNEYS.

FORCED AIR FREEZER One of the features of this invention is to provide a refrigeration apparatus, including an air duct means, that distributes the air along the inner surfaces of walls defining the storage enclosure in the apparatus so that the temperature throughout the storage enclosure is substantially uniform with a very small temperature difference between any portion of the enclosure space and any other portion of this space.

Other features and advantages of the invention will be apparent from the following description of one embodiment taken in conjunction with the accompanying drawings. Of the drawings:

P10. 1 is a semidiagrammatic front elevational view of an upright household freezer embodying the invention but omitting the door that closes the usual front access opening.

H6. 2 is a vertical sectional view substantially along line 2-2 of FIG. 1 but including the from access door.

In the embodiment illustrated in the drawings the freezer is an upright freezer that comprises boundary walls defining a storage enclosure space 11 that may be separated into sections in the usual manner by the usual shelves 12. These boundary walls that define the enclosure 11 comprise a top wall 13, a pair of opposite sidewalls 14, a front wall 15, a bottom wall 16 and a rear wall 17. These walls together comprise a cabinet 18 in the bottom of which is the usual machinery compartment 19.

Located to be substantially coextensive with a major portion of one of the walls -18, here illustrated as the rear wall 17, is an air duct means 20 that is defined by the interior surface 21 of the rear wall 17 and a baffle 22 spaced forwardly of the surface 21. The baffle 22 which as shown in FIG. 1 is generally rectangular, has top 23 and side 24 edges spaced from the corresponding surfaces 25 and 26 of the top 13 and side M walls to provide the spaces 27 and 28 that comprise peripheral discharge means at these edges.

The top and side edges 23 and'24 of the baffle 22 are provided with right angle flanges illustrated at 29 in FIG. 2 that extend toward the rear wall surface 21, and are closely spaced therefrom to partially restrict air discharge from duct 20 in order to ensure an even discharge of air around the periphery of baffle 22.

As is evident from F168. 1 and 2, the spaces 27 and 28 which comprise the peripheral discharge means for the air duct are located adjacent the top 13 and side 14 wall corners so that the angular relationship of these walls with the rear wall 17 serves to direct the air exiting around the edges of the baffle 22 along the inner surfaces of the top and sidewalls and toward the front wall 15 as indicated by the air flow arrows in the F165. This produces a wiping action not only along the inner surfaces of the top 13 and side 14 walls but also directs this air toward the inner surface of the front wall 15 and down this wall toward the bottom of the enclosure space 11.

Thus, the flow of air through the air duct 20 and along the wall surfaces 21, 25 and 26 as illustrated by the arrows M and past the region of the door gasket 31 and the inner surface of door 311 comprising wall 15 as illustrated by the arrows 15 serves to wipe the inner surfaces of the walls and immediately pick up and intermingle warm air from the interior warm spots along these walls. As can be noted from the drawings, this pickup of warm air created by the warm spots is immediate.

The duct 20 is provided with an air inlet means 46 adjacent one end of the duct for receiving air from the enclosure 11 including the air from along the second or front wall 15. This air inlet means in the embodiment illustrated is adjacent the lower end of the duct 20 which communicates directly with a housing 32 that is spaced a greater distance forwardly of the rear wall surface 21 than is the baffle 22 in order to provide space for a lower finned refrigerant evaporator 33 and an upper power driven blower means 34 in the form of a fin as illustrated.

The bottom of the housing 32 beneath the evaporator 33 communicates with the enclosure space 11 to receive air therefrom by way of openings 35 which are adjacent the bottom wall 16 of the cabinet. Air is also received into the bottom of the housing 32 from a passage 36 along the inner surface of the bottom wall 16 that communicates with the bottom edge of the door 30.

As stated earlier, the refrigerated air duct 20 is substantially coextensive with a major portion of the rear wall surface 21 in order to achieve uniform distribution of the refrigerated air through the enclosure 11. This major portion is more than 50 percent of this surface so that there will be no great temperature gradient between any pair of spatial portions Within the enclosure 11. ln one embodiment of the invention the temperature difference between any pair of portions of the interior space was never more than about 2 or 3 F. once the space 11 had reached a stable temperature condition, that is, once the interior and items stored therein had reached a fixed refrigeration temperature. In this embodiment the major portion of the one wall with which the air duct was coextensive was about 70 percent of the wall surface.

Even when the storage space 11 contains a considerable amount of stored material such as frozen food the air flow conditions which as described contribute to the even temperature through the space 11 are not changed because the stored food does not materially interfere with the air flow pattern.

This is true because the air flow is along and wipes the wall surfaces rather than being primarily through the center of the space. In the illustrated air flow pattern the air in the duct 20 of course wipes the rear wall surface 21 first before flowing along and wiping the surfaces of the top 13 and side 14 walls. Any warm spot surfaces along these walls due to heat leaks through the walls are immediately refrigerated and the heat leakage nullified by immediate mingling with the flowing refrigerated air stream. Heat leaks of course are present in all refrigerated structures because perfect .insulation from the exterior is impossible to attain. Then the flowing air is directed by the walls themselves past the gasket 31, down along the interior of the door 15 and finally along the surface 36 of the bottom wall 16 and from there back into the bottom of the housing 32 for flow upwardly through the evaporator 33 and back to the fan 34 for recirculation.

[n the illustrated embodiment which is an upright food freezer there is provided a flow control valve means 37 in the duct defining baffle 22 that is movable between open and closed positions for passing refrigerated air directly from the air duct 20 into the enclosure space 11 where it can be used for direct contact with unfrozen materials such as foods in order that they will be frozen rapidly and completely. In the illustrated embodiment this valve means comprises a slidable shutter or plate 38 that is slidable back and forth horizontally to align a series of openings 39 in the shuttur 38 with a similar series of openings 40 in the portion 11 of the baffle 22. As can be seen, the shutter 38 is behind the bafile portion 41 and is operated by means of a protruding handle 42. When the shutter 33 is moved to align its openings 39 with the openings 40 then refrigerated air flows dire tly through the aligned openings into the enclosure space 11. Unfrozen food placed on a shelf 43 in front of these openings will be immediately frozen. After this has occurred the shutter 38 may then be moved to the right, in the illustrated embodiment, so that the openings 39 and 450 are out of alignment with the result that the air duct and air distribution means function in the described manner to maintain the substantially uniform temperature throughout the interior of the cabinet.

We claim:

1. Refrigeration apparatus having substantially uniform temperature throughout a storage enclosure therein, comprising: boundary walls defining said enclosure; an air duct means substantially coextensive with a major portion of one of said walls and having edges adjacent to but spaced from others of said walls; peripheral discharge means at said air duct means edges for providing streams of air at said edges directed along said adjacent walls and toward a second wall that is directly opposite said one wall for flow along said second wall; an air inlet means adjacent one end of said duct means for receiving air from said enclosure including air from along said second wall; means for forcing air through said air duct; and means for refrigerating said duct air.

2, The apparatus of claim 1 wherein said second wall comprises an access door having edge sealing means past which said air flows thereby carrying with it any exterior air leakage past said sealing means.

3. The apparatus of claim 1 wherein said means for forcing air through said duct means comprises blower means adjacent said duct air inlet means.

4. The apparatus of claim 1 wherein said means for refrigerating said duct air comprises a refrigerant evaporator, a housing therefor communicating with said storage enclosure and with said duct means entrance, and blower means in said housing for forcing air over said evaporator and into and through said duct means.

5. The apparatus of claim 4 wherein said evaporator, housing and blower means are positioned at said one wall adjacent said major portion of said one wall and adjacent said air inlet means to the duct means.

6. The apparatus of claim 2 wherein said one wall is a rear wall, said adjacent walls are top and sidewalls and said other wall is a front wall.

7. The apparatus of claim 6 wherein said means for refrigerating said duct air comprises a refrigerant evaporator, a housing therefor communicating with said storage enclosure and with said duct means entrance, and blower means in said housing for forcing air over said evaporator and into and through said duct means, and said evaporator, housing and blower means are positioned at said one wall adjacent said major portion of said one wall and adjacent said air inlet means to the duct means and above a bottom wall of said enclosure.

8. Refrigeration apparatus having substantially uniform temperature throughout a storage enclosure therein, comprising: boundary walls defining said enclosure; an air duct means substantially coextensive with a major portion of one of said walls and having edges adjacent others of said walls; peripheral discharge means at said air duct means edges for directing air from said duct along said adjacent walls and toward a second wall that is directly opposite said one wall for flow along said second wall; an air inlet means adjacent one end of said duct means for receiving air from said enclosure including air from along said second wall; means for forcing air through said air duct; means for refrigerating said duct air; and air flow control valve means in said duct means movable between open and closed positions for passing refrigerated air directly into said storage enclosure.

9. The apparatus of claim 8 wherein said valve means comprises a slidable plate having openings adapted to register with openings in said duct means. 

1. Refrigeration apparatus having substantially uniform temperature throughout a storage enclosure therein, comprising: boundary walls defining said enclosure; an air duct means substantially coextensive with a major portion of one of said walls and having edges adjacent to but spaced from others of said walls; peripheral discharge means at said air duct means edges for providing streams of air at said edges directed along said adjacent walls and toward a second wall that is directly opposite said one wall for flow along said second wall; an air inlet means adjacent one end of said duct means for receiving air from said enclosure including air from along said second wall; means for forcing air through said air duct; and means for refrigerating said duct air.
 2. The apparatus of claim 1 wherein said second wall comprises an access door having edge sealing means past which said air flows thereby carrying with it any exterior air leakage past said sealing means.
 3. The apparatus of claim 1 wherein said means for forcing air through said duct means comprises blower means adjacent said duct air inlet means.
 4. The apparatus of claim 1 wherein said means for refrigerating said duct air comprises a refrigerant evaporator, a housing therefor communicating with said storage enclosure and with said duct means entrance, and blower means in said housing for forcing air over said evaporator and into and through said duct means.
 5. The apparatus of claim 4 wherein said evaporator, housing and blower means are positioned at said one wall adjacent said major portion of said one wall and adjacent said air inlet means to the duct means.
 6. The apparatus of claim 2 wherein said one wall is a rear wall, said adjacent walls are top and sidewalls and said other wall is a front wall.
 7. The apparatus of claim 6 wherein said means for refrigerating said duct air comprises a refrigerant evaporator, a housing therefor communicating with said storage enclosure and with said duct means entrance, and blower means in said housing for forcing air over said evaporator and into and through said duct means, and said evaporator, housing and blower means are positioned at said one wall adjacent said major portion of said one wall and adjacent said air inlet means to the duct means and above a bottom wall of said enclosure.
 8. Refrigeration apparatus having substantially uniform temperature throughout a storage enclosure therein, comprising: boundary walls defining said enclosure; an air duct means substantially coextensive with a major portion of one of said walls and having edges adjacent others of said walls; peripheral discharge means at said air duct means edges for directing air from said duct along said adjacent walls and toward a second wall thAt is directly opposite said one wall for flow along said second wall; an air inlet means adjacent one end of said duct means for receiving air from said enclosure including air from along said second wall; means for forcing air through said air duct; means for refrigerating said duct air; and air flow control valve means in said duct means movable between open and closed positions for passing refrigerated air directly into said storage enclosure.
 9. The apparatus of claim 8 wherein said valve means comprises a slidable plate having openings adapted to register with openings in said duct means. 